Consistent SDNs through Network State Fuzzing

The conventional wisdom is that a software-defined network (SDN) operates under the premise that the logically centralized control plane has an accurate representation of the actual data plane state. Nevertheless, bugs, misconfigurations, faults or attacks can introduce inconsistencies that undermine correct operation. Previous work in this area, however, lacks a holistic methodology to tackle this problem and thus, addresses only certain parts of the problem. Yet, the consistency of the overall system is only as good as its least consistent part. Motivated by an analogy of network consistency checking with program testing, we propose to add active probe-based network state fuzzing to our consistency check repertoire. Hereby, our system, PAZZ, combines production traffic with active probes to continuously test if the actual forwarding path and decision elements (on the data plane) correspond to the expected ones (on the control plane). Our insight is that active traffic covers the inconsistency cases beyond the ones identified by passive traffic. PAZZ prototype was built and evaluated on topologies of varying scale and complexity. Our results show that PAZZ requires minimal network resources to detect persistent data plane faults through fuzzing and localize them quickly

Actual and potential impact of air pollution on Italian forests: results from the long-term national forest monitoring networks under the ICP Forests

Actual and potential pressure and impacts of air pollution have been summarized by using the dataseries of the Italian forest monitoring networks (CONECOFOR), mostly on the basis of evaluations carried out within the LIFE project SMART4Action. Trends in air pollution shows only few important reductions (e.g.: sulphate and ozone). The impacts on forest health status, increments and standing volumes, plant diversity, soil and nutrient are discussed. Evidences of risk are also reported, mainly due to N deposition, on all the response factors

Maximum rates of N2 fixation and primary production are out of phase in a developing cyanobacterial bloom in the Baltic Sea

Although N2-fixing cyanobacteria contribute significantly to oceanic sequestration of atmospheric CO2, little is known about how N2 fixation and carbon fixation (primary production) interact in natural populations of marine cyanobacteria. In a developing cyanobacterial bloom in the Baltic Sea, rates of N2 fixation (acetylene reduction) showed both diurnal and longer-term fluctuations. The latter reflected fluctuations in the nitrogen status of the cyanobacterial population and could be correlated with variations in the ratio of acetylene reduced to 15N2 assimilated. The value of this ratio may provide useful information about the release of newly fixed nitrogen by a cyanobacterial population. However, although the diurnal fluctuations in N2 fixation broadly paralleled diurnal fluctuations in carbon fixation, the longer-term fluctuations in these two processes were out of phase

Antiradical activity of phenolic metabolites extracted from grapes of white and red Vitis vinifera L. cultivars

A diet rich in plant foods is strongly recommended for its beneficial effect on human health. In fact, plant secondary metabolites may exert various biological activities on mammalian cells. Among them, phenolics are excellent natural antioxidants able to rescue cell redox unbalance responsible for the onset of different pathologies. For these reasons, the present work was focused on the study of grape extracts obtained from eight different Italian Vitis vinifera cultivars, quite rare in Italian viticulture and not yet completely chemically characterized. For each preparation, total simple phenolic, flavonoidic and anthocyaninic content was measured through spectrophotometrical assays, while detailed biochemical profile was revealed by LC-MS analyses. In order to valorize the products of these varieties and increase our knowledge about their potential healthy role, the antioxidant power of the samples was evaluated by two different in vitro antiradical tests: DPPH and FRAP. Moreover, free radical scavenging properties of eleven grape pure compounds were investigated, with the aim to: a) compare their real antiradical property with the theoretical one; b) identify which one of them possessed the best bioactivity; c) understand how they might singularly contribute to the nutraceutical effect of the whole grapevine phytocomplex

Ultrastructure and development of the floral nectary from Borago officinalis L. and phytochemical changes in its secretion

Although Boraginaceae have been classified as good sources of nectar for many insects, little is still known about their nectar and nectaries. Thus, in the present contribution, we investigated the nectar production dynamics and chemistry in Borago officinalis L. (borage or starflower), together with its potential interaction capacity with pollinators. A peak of nectar secretion (∼5.1 μL per flower) was recorded at anthesis, to decrease linearly during the following 9 days. In addition, TEM and SEM analyses were performed to understand ultrastructure and morphological changes occurring in borage nectary before and after anthesis, but also after its secretory phase. Evidence suggested that nectar was transported by the apoplastic route (mainly from parenchyma to epidermis) and then released essentially by exocytotic processes, that is a granulocrine secretion. This theory was corroborated by monitoring the signal of complex polysaccharides and calcium, respectively, via Thiéry staining and ESI/EELS technique. After the secretory phase, nectary underwent degeneration, probably through autophagic events and/or senescence induction. Furthermore, nectar (Nec) and other flower structures (i.e., sepals, gynoecia with nectaries, and petals) from borage were characterized by spectrophotometry and HPLC-DAD, in terms of plant secondary metabolites, both at early (E-) and late (L-) phase from anthesis. The content of phytochemicals was quantified and discussed for all samples, highlighting potential biological roles of these compounds in the borage flower (e.g., antimicrobial, antioxidant, staining effects). Surprisingly, a high significant accumulation of flavonoids was registered in L-Nec, with respect to E-Nec, indicating that this phenomenon might be functional and able to hide molecular (e.g., defence against pathogens) and/or ecological (e.g., last call for pollinators) purposes. Indeed, it is known that these plant metabolites influence nectar palatability, encouraging the approach of specialist pollinators, deterring nectar robbers, and altering the behaviour of insects

Bilingualism provides a neural reserve for aging populations.

It has been postulated that bilingualism may act as a cognitive reserve and recent behavioral evidence shows that bilinguals are diagnosed with dementia about 4-5 years later compared to monolinguals. In the present study, we investigated the neural basis of these putative protective effects in a group of aging bilinguals as compared to a matched monolingual control group. For this purpose, participants completed the Erikson Flanker task and their performance was correlated to gray matter (GM) volume in order to investigate if cognitive performance predicts GM volume specifically in areas affected by aging. We performed an ex-Gaussian analysis on the resulting RTs and report that aging bilinguals performed better than aging monolinguals on the Flanker task. Bilingualism was overall associated with increased GM in the ACC. Likewise, aging induced effects upon performance correlated only for monolinguals to decreased gray matter in the DLPFC. Taken together, these neural regions might underlie the benefits of bilingualism and act as a neural reserve that protects against the cognitive decline that occurs during aging

Profile and potential bioactivity of the miRNome and metabolome expressed in Malva sylvestris L. leaf and flower

Malva sylvestris L. (common mallow) is a plant species widely used in phytotherapy and ethnobotanical practices since time immemorial. Characterizing the components of this herb might promote a better comprehension of its biological effects on the human body but also favour the identification of the molecular processes that occur in the plant tissues. Thus, in the present contribution, the scientific knowledge about the metabolomic profile of the common mallow was expanded. In particular, the phytocomplex of leaves and flowers from this botanical species and the extraction capacity of different concentrations of ethanol (i.e., 95%, 70%, 50%, and 0%; v/v in ddH2O) for it were investigated by spectrophotometric and chromatographic approaches. In detail, 95% ethanol extracts showed the worst capacity in isolating total phenols and flavonoids, while all the hydroalcoholic samples revealed a specific ability in purifying the anthocyanins. HPLC–DAD system detected and quantified 20 phenolic secondary metabolites, whose concentration in the several extracts depended on their own chemical nature and the percentage of ethanol used in the preparation. In addition, the stability of the purified phytochemicals after resuspension in pure ddH2O was also proved, considering a potential employment of them in biological/medical studies which include in vitro and in vivo experiments on mammalian models. Here, for the first time, the expressed miRNome in M. sylvestris was also defined by Next Generation Sequencing, revealing the presence of 33 microRNAs (miRNAs), 10 typical for leaves and 2 for flowers. Then, both plant and human putative mRNA targets for the detected miRNAs were predicted by bioinformatics analyses, with the aim to clarify the possible role of these small nucleic acids in the common mallow plant tissues and to try to understand if they could exert a potential cross-kingdom regulatory activity on the human health. Surprisingly, our investigations revealed that 19 miRNAs out of 33 were putatively able to modulate, in the plant cells, the expression of various chromosome scaffold proteins. In parallel, we found, in the human transcriptome, a total of 383 mRNAs involved in 5 fundamental mammalian cellular processes (i.e., apoptosis, senescence, cell-cycle, oxidative stress, and invasiveness) that theoretically could be bound and regulated by M. sylvestris miRNAs. The evidence collected in this work would suggest that the beneficial properties of the use of M. sylvestris, documented by the folk medicine, are probably linked to their content of miRNAs and not only to the action of phytochemicals (e.g., anthocyanins). This would open new perspectives about the possibility to develop gene therapies based on miRNAs isolated from medicinal plants, including M. sylvestris

Assessing molecular diversity among 87 species of the Quercus L. genus by RAPD markers

Oaks (Quercus sp.) are among the most ecologically and economically important woody Angiosperms of the northern hemisphere. Nowadays, the reduction of Quercus biodiversity is becoming a matter of global concern, and several oak species have been included in the IUCN Red List of Threatened Species. Consequently, characterization and preservation strategies for the oak germplasm are largely promoted. Thus, in this work, the genetic diversity existing among 87 different Quercus species was assessed using the RAPD markers, in order to better typify these specimens, to show the amazing DNA variability of this plant genus, and to confirm or infer new putative molecular correlations. Our data were discussed taking into consideration the phylogenetic and phylogeographic relationships previously proposed by the literature. In general, the obtained results corroborated that the evolutionary pattern of Quercus genus has been extremely intricate and continues to change rapidly, making it difficult to be fully resolved. The evidence collected in the present investigation would confirm the complex evolution of the oaks, due to their high migration capacity, divergence rate, and hybridization propensity. This research, performed on a so large series of species, represents a positive contribution for highlighting the genetic diversity within collections of Quercus germplasm and favouring ex-situ conservation programmes

Anabasis articulata (Forssk.) Moq. food aqueous extract triggers oxidative stress-induced senescence and reduces metastatic power in MDA-MB-231 cells

Ancient ethnobotanical practices handed down through traditional knowledge are still commonly employed to treat various pathologies, although the scientific reasons underlying their biological effects have not been clarified yet. In this contribution, the potential antitumoral activity of the aqueous extract from A. articulata (AAE) was investigated to validate the hypothesis of the Algerian folk medicine which would suggest this plant derivative as a functional food for treating breast cancer. A. articulata phytocomplex, isolated by maceration following exactly the African recipe, has been already characterized by our research group in previous works. Thus, the antiproliferative function of AAE against MDA-MB-231, a highly aggressive human breast adenocarcinoma cell line, was evaluated. Slowing down of cell growth, absence of cytotoxicity and DNA fragmentation, and cell cycle arrest at the G2/M phase were observed after treatment with AAE at different doses (0.3–6 mg of dried plant material equivalent per mL of culture medium) for 24 and 48 h. Wound and transwell assays proved that AAE possessed both antimigration and antiinvasive capacities, evidence also supported by molecular analyses focused on Metalloproteases (MMP-2 and MMP-9), Vimentin and ανβ3-Integrin. These results, together with the demonstration of the activation of p53/p21WAF1/Cip1/p27Kip1 pathway and the increase of oxygen reactive species levels, suggested that AAE triggered a senescence process. The final confirmation was obtained by a specific kit staining senescent cells. All our data would explain the efficacy of the Algerian medicinal remedy based on the intake of the investigated functional plant food and would highlight the basics for developing novel natural pharmacological products based on AAE and showing preventive and therapeutic antineoplastic potentialities against highly aggressive breast cancers